#!/bin/bash
a=$1
cal=$2
b=$3
if [ $cal = "add" ];then
	c=$[a+b]
	echo "$a + $b = $c"
elif [ $cal = "dec" ];then
	c=$[a-b]
	echo "$a - $b = $c"
elif [ $cal = "mul" ];then
	c=`expr $a \* $b `
	echo "$a * $b = $c"
elif [ $cal = "div" ];then
	c=$[$a/$b]
	echo "$a / $b = $c"
else 
	c=$[$a%$b]
	echo "$a % $b = $c"
fi
